Conventionally, an insulated gate bipolar transistor (hereinafter, IGBT) has a high input impedance of a field effect transistor and a high current drive capability of a bipolar transistor, and is particularly suitably used as a power switching device.
In a semiconductor device of this type, it is necessary to improve the radiation performance in order to prevent destruction, etc. of the semiconductor device due to a thermal runaway effect. Thus, the semiconductor device is adhered to a support plate (heat sink) also serving as a radiator plate via solder or the like. Heat generated by the semiconductor device is radiated to the outside from the radiator plate via the surface of the semiconductor device and the solder or the like.
However, particularly, a power semiconductor device has many semiconductor operating regions that are formed on a single semiconductor substrate in belt forms or island forms, in order to have an increased current capacity. As a result, the center part of the semiconductor device gains the heat emitted from the peripheral part of the semiconductor device, thus cannot achieve a radiation performance favorably.
Hence, there has been developed a semiconductor device in which the emitter regions near a gate bus line formed at the center part of the semiconductor device are formed intermittently, as disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 2004-228553.